1. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p1 The Rotational Spectrum of H 15 NO 3 : All States Below 1000 cm -1 Douglas T. Petkie, Mark Kipling, Ashley Jones Department of Physics, Wright State University Paul Helminger Department of Physics, University of South Alabama Ivan Medvedev, Atsuko Maeda Department of Physics, Ohio State University Brian J. Drouin, Charles Miller Jet Propulsion Laboratory, California Institute of Technology International Symposium on Molecular Spectroscopy 61 th Meeting June 19-23, 2006 The Ohio State University Columbus, Ohio

2. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p2 Review article “Recent progress in the analysis of HNO3 spectra” by A. Perrin, Spectrochimica Acta Part A 54 (1998) 375–393. 14 N Overview Important atmospheric constituent TG02 –Perrin, et al. TG02  MIPAS Interesting spectroscopy –Strong interacting states –Torsional splitting N OO O H

3. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p3 Nitric Acid Isotopes N 15 O 18 O 17 Drouin, et al. JMS, 236 29-34 (2006) Laboratory motivating factors – high lying vibrational states of the parent species Laboratory spectra

4. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p4 FAst Scan Submillimeter Spectroscopic Technique (FASSST) spectrometer Interference fringes Spectrum InSb detector 1 InSb detector 2 Ring cavity: L~15 m Mylar beam splitter 1 Mylar beam splitter 2 High voltage power supply Slow wave structure sweeper Aluminum cell: length 6 m; diameter 15 cm Trigger channel /Triangular waveform channel Signal channel BWO Magnet Lens Filament voltage power supply Length ~60 cm Stepper motor Reference channel Lens Stainless steel rails Path of microwave radiation Preamplifier Frequency roll-off preamplifier Reference gas cell Glass rings used to suppress reflections Data acquisition system Computer WI04 Medvedev, et al. WI04

5. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p5 The JPL Frequency Multiplication Submillimeter Spectrometer 83558A HP8340b SR830 M1611/2D HP FG AM/FM/TM sync InSb or Si gas pre-amp vacuum pump sample sweep synthesizer YIG filter mm-wave module MMIC amps submm multipliers waveguide feedhorns sample cell He cooled detector waveform generator lock-in-amplifier PC GPIB modulation DAQ tuning voltage WI08 Drouin, et al. WI08

6. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p6 Laboratory Spectra JPL: 74-109, 402-410, 639-656, 800-850 GHz –Frequency Multiplier Spectrometer OSU: 118-186, 192-377 GHz –FASSST system at Temp ~ 180 o C predicted spectrum JPL OSU

7. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p7 R and Q Branches FASSST Spectra Simulation of ground state R Q

8. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p8 15 N Spectra is Very Similar to 14 N N is near the center of mass R-branch transitions are only slightly shifted 15 N 14 N

9. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p9 Previous Studies High resolution infrared study of 15 N F. Keller, A. Perrin, J.-M. Flaud, J. W. C. Johns, Z. Lu, and E. C. Looi, J. Mol. Spectrosc. 191, 306–310 (1998) – 6, 7, 8, 9 bands A. Perrin and Robert Mbiaké, J. Mol. Spectrosc. 237 (2006) 27–35 – 5, 2 9 bands mw/mm/sub-mm wave studies… – 15 N Millen and Morton, J. Chem. Soc. 1523-1528 (1960) – 14 N used to predict 15 N spectra D. T.Petkie, P. Helminger, R. A. H. Butler, S. Albert, and F. C.De Lucia J. Mol. Spectrosc. 218 127–130 (2003) –gs, 6, 7, 8, 9 states D. T. Petkie, T. M. Goyette, P. Helminger, H. M. Pickett, and F. C. De Lucia, J. Mol. Spectrosc. 208, 121–135 (2001) – 5, 2 9 states

10. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p10 Ground State Previous MW work: –Millen and Morton, J. Chem. Soc. 1523-1528 (1960) “Accidental” beginning –mistaken for the 6 1 7 1 vibrational state of the normal species Watson A-reduced Hamiltonian in the I r representation –For all fits, SPFIT/SPCAT (H. Pickett / JPL) 844 transitions to 844 GHz J max = 86, K a,max = 68, K c,max = 66

11. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p11  8 = 1 Vibrational State Watson A-reduced Hamiltonian in the I r representation 715 transitions to 656 GHz –66 kHz rms J max = 72, K a,max = 47, K c,max = 49

12. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p12  6 = 1 and  7 = 1 Vibrational States Watson A-reduced Hamiltonian in the I r representation Coriolis Interaction:  7 = 1 –761 transitions to 838 GHz 74 kHz rms –J max = 70, K a,max = 50, K c,max = 65  6 = 1 –735 transitions to 832 GHz 71 kHz rms –J max = 71, K a,max = 50, K c,max = 65 With out the Coriolis interaction –240 kHz rms for isolated states w/o an interaction term –35 lines effected: J > 55 and mostly K c ~ 23, 24, 25 for  7 = 1 (25, 26, 27 for  6 = 1) and J ~ 70 and K c = 30, 31 for  6 = 1 obs-calc not more than 10 MHz, mostly ~0.5 – 1 MHz

13. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p13 Coriolis Interactions and Centrifugal Distortion For nitric acid, the Coriolis interaction is not obvious in the centrifugal distortion constants T. Tanaka, Y. Morino, J. Mol. Spectrosc. 5 (1969) 436-448. w/o

14. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p14 Determinable Combinations of Coefficients Determinable Combinations of Coefficients in Terms of the Spectroscopic Constants of the A Reduction [Gordy and Cook] D. T. Petkie, P. Helminger, M. Behnke, I. R. Medvedev, and F. C. De Lucia, J. Mol. Spectrosc. 233 189-196 (2005)

15. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p15 Coriolis Interactions and Centrifugal Distortion For 14 N from D. T. Petkie, P. Helminger, M. Behnke, I. R. Medvedev, and F. C. De Lucia, J. Mol. Spectrosc. 233 189-196 (2005) Well-behaved and a better diagnostic for nitric acid

16. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p16 Torsional Splitting: 9 1 and 9 2 States IAS (Internal Axis System) Hamiltonian –SPFIT, SPCAT (Pickett /JPL) I R representation in the A-reduction (z = a, x = b, y = c) N OO O H

17. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p17  9 = 1 Vibrational State In addition to early references: –C. D. Paulse, L. H. Coudert,T. M. Goyette, R. L. Crownover, P. Helminger, and F. C. De Lucia J Mol Spectrosc. 177, 9–18 (1996) Internal Axis System Hamiltonian –Watson-like A-reduced Hamiltonian in the I r representation 1193 transitions to 842 GHz –82 kHz rms J max = 73, K a,max = 59, K c,max = 65 Torsional splitting in MHz – 14 N 1.170(4) – 15 N 1.212(3)

18. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p18  5 = 1 and  9 = 2 Vibrational States Strongly Interacting states –A. Perrin and Robert Mbiaké, J. Mol. Spectrosc. 237 (2006) 27–35TG01 –A. Perrin, J. Orphal, J.-M. Flaud, S. Klee, G. Mellau, H. Mäder, D. Walbrodt, and M. Winnewisser, J. Mol. Spectrosc. 228 (2004) 375–391 –D. T. Petkie, T. M. Goyette, P. Helminger, H. M. Pickett, and F. C. De Lucia, J. Mol. Spectrosc. 208, 121–135 (2001) IAS (Internal Axis System) Hamiltonian Interaction terms –Fermi and c-type Coriolis terms

19. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p19  5 = 1 and  9 = 2 Vibrational States Data set and analysis –465  5 = 1 transitions; 502  9 = 2 transitions; 79  5 = 1   9 = 2 transitions –81 kHz rms with 53 parameters –J max = 60, K a,max = 41, K c,max = 52 “Induced” splitting model –only the  9 = 2 state has a torsional splitting –F o Fermi terms mixes the wave function and induces a torsional splitting on  5 = 1 Fitted torsional splitting parameter in  9 = 2 43.03(1) for N 15 compared to 43.15(1) for N 14 Observed splittings: –  9 = 2 35.4 for N 15 compared to 25.4 MHz for N 14 –  5 = 1 7.7 MHz for N 15 compared to 17.7 MHz for N 14

20. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p20 Comparisons Mixing: – 15 N  82/18 % compared to 59/41 % for 14 N Much weaker interaction due to a shift in the band origin for  5 = 1 With Perrin et al. (2006) band origins, the Fermi term is nearly identical to 14 N as expected In excellent agreement with the very recently published analysis of Perrin et al. (2006) –Using a F o Fermi term fixed to that of 14 N, the fitted band origin difference between  5 = 1 and  9 = 2 was 14.4469 cm -1 compared to Perrin et al. of 14.4479 cm -1. –The torsional splitting predicts an intensity ratio of Int(2 9 )/Int( 5 ) = 0.218 compared to the measured value of Perrin et al. Int(2 9 )/Int( 5 ) ~ 0.23

21. 22 June 200661 st International Symposium on Molecular SpectroscopyPetkie – RE07-p21 Conclusions Solid mm/submm analyses for all states below 1000 cm -1 are available for H 15 NO 3 Observed torsional splitting in the  9 = 1,  5 = 1 and  9 = 2 Results and analyses closely followed those of 14 N Thank you for your time